Pressure control for sheet feed means in duplicating machine



Nov. 13, 1962 E. M. SPRINGER 3,0 3,711 PRESSURE CONTROL FOR SHEET FEEDMEANS IN DUPLICATING MACHINE Filed Feb. 26, 1959 4 Sheets-Sheet 1.Z/7Z/6/7Z'0F: Edward M Jpn/g6) 144m, 49%,

Nov. 13, 1962 E. M. SPRINGER PRESSURE CONTROL F 3,063,711 OR SHEET FEEDMEANS IN DUPLICATING MACHINE 4 Sheets-Sheet 2 Filed Feb. 26, 1959 S d WQ Q o m a Q Q o Q E O O O Qm m m3 vm mmr E E Pod 5 A m w & w NE N d E.Q%\ I \Q% f 0 NE g 9 ms a) mum, Em Q g E 3 QQ w mm m Nov. 13, 1962 E. M.SPRINGER PRESSURE CONTROL FOR SHEET FEED MEANS IN DUPLICATING MACHINE 4Sheets-Sheet 3 Filed Feb. 26, 1959 ffiue nwr: Edward M. Spa/ya"51941512.. $9M, I 6M W 1962 E. M. SPRINGER 3,063,711

PRESSURE CONTROL FOR SHEET FEED MEANS IN DUPLICATING MACHINE Filed Feb.26, 1959 4 Sheets-Sheet 4 Jfiuentor: Edward M Springer By W 19M,

Unite ties ii The present invention relates to duplicating machines andmore particularly to control for feed means utilized for feeding copysheets from the usual feed table into the duplicating machine.

In duplicating machines generally, a stack of copy sheets is placed on afeed table mounted in the duplicating machine, and the sheets are fedfrom the stack, singly, to the machine. Means is included for feedingthe sheets, while means is also utilized for controlling the stack ofsheets so that only the single top sheet is fed at a time and theremaining sheets are held against removal.

In mechanisms of this general kind, the feeding means is arranged forimposing a certain predetermined friction pressure on the top copysheet, which is of course necessary in order to remove that copy sheet.For best results, the pressure exerted by the feeding means should bevaried according to the weight or thickness of the copy sheets beingused. For example, greater pressure should be used in the case of heavycopy sheets than in the case of lighter or thinner sheets, since a givenpressure for heavy sheets may result in more than one light sheet beingfed at a time, while on the other hand, a pressure set for light sheetsmay not effect feeding of heavy sheets at all. Heretofore, there has notbeen an entirely satisfactory means for varying the pressure of thefeeding means of the general type involved.

An object therefore of the invention is to provide novel means forvarying the pressure of the feeding means of the character abovereferred to, in a duplicating machine.

Another object is to provide means of the foregoing character that iscapable of varying the pressure of the feeding means throughout a rangefrom a positive pressure to a negative pressure.

Still another object is to provide means of the foregoing generalcharacter that may be adjusted for varying the pressure while theduplicating machine is in operation.

A further object is to provide pressure controlling means of the generalcharacter above referred to which is of extremely simple construction. 1

Another and more specific object is to provide pressure controllingmeans of the foregoing general character that utilizes a novelover-center spring-controlled arrangement for producing the positive andnegative pressures in the feeding means.

A still further object is to provide novel feed wheels for gripping thetop copy sheet of the stack and feeding it to the duplicating machine,and a shaft for demountably supporting the feed wheels and forsupporting them for adjustment therealong.

Other objects and advantages of the invention will appear from thefollowing detailed description taken in conjunction with theaccompanying drawings in which- FIGURE 1 is a frot elevational view of aduplicating machine embodying the features of the present invention;

FIGURE 2 is a diagrammatic view of a portion of the interior of theduplicating machine, orientated in 'a vertical fore-and-aft direction,showing certain of the essential operating members of the machine;

FIGURE 3 is a side elevational view of the machine taken on line 3-3 ofFIGURE 1, but with the side housing member removed and showing pressurecontrol means of the invention;

FIGURE 4 is a large scale view of the pressure control means included inFIGURE 3;

FIGURE 5 is a view from the left of FIGURE 4 and additionally includinga side plate of the machine on which the other elements are mounted;

FIGURE 6 is a front elevational view of the feed wheels and shaft shownin FIGURE 1;

FIGURE 7 is a view taken on line i7 of FIGURE 6;

FIGURE 8 is a sectional view taken on line 88 of FIGURE 7;

FIGURE 9 is a sectional view taken on line 9-9 of FIGURE 8;

FIGURE 10 is a view similar to FIGURE 7 but with the mounting shaftomitted;

FIGURE 11 is a view oriented according to FIGURE 10, but showing onlythe central portion of the wheel and with the insert elements omitted;

FIGURE 12 is a perspective view of a portion of one end of the shaft onwhich the feed wheels are mounted; and

FIGURE 13 is a sectional view taken on line 1313 of FIGURE 6.

Referring now in detail to the drawings, attention is directed first toFIGURES 1 to 3 for a representation of the duplicating machine as awhole in which the pressure control means of the present invention isincorporated. The particular kind of duplicating machine utilized forcarrying out-the objects of the invention is not an essential part ofthe invention except that the. invention is applied to a kind ofduplicating machine having means for feeding copy sheets from a feedtable into the machine. The pressure control means of the inventioncontrols the pressure applied by this feeding means on the copy sheetswhich are being fed into the machine. By way of 6X1 ample, theduplicating machine here illustrated is of the. kind illustrated in fulland claimed in my copending ap plication Serial Number 661,460, filedMay 24, 1957, now Patent No. 2,975,707, dated March 21, 1961.

Such duplicating machine is indicated at 16 and as illustrated in FIGURE1 includes apair of spaced-apart side plates 18 forming the main portionof a framwork for supporting the other parts of the machine. Mounted inand between the side plates are such instrumentalitiesas a drum 20, afluid tank 22, a driving motor 24, as well as feed means 26 forming aprincipal portion of the em-. bodiment of the present invention.

O-utwardly of and mounted on the side plates 18 are housing members 28for enclosing certain operating parts mounted on the outer sides of theside plates. FIGURE 3 is a view from the right hand side of FIGURE 1 asindicated by the line 3-3 but with the respective housing member 28removed and exposing the outer side of the corresponding side plate 18and the operating parts thereon. The pressure control means forming thesubject matter of the present invention includes as a principal partthereof certain linkage indicated in its entirety at 30 in FIGURE 3,this view showing its orientation with the other parts of theduplicating machine. It is shown in greater detail in FIGURES 4 and 5. 1

Referring again to the duplicatiing machine itself, attention isdirected to FIGURE 2 which shows diagram:

/ matically the main operating parts within the machine utilized forimprinting on the copy sheets as they are passed through the'machine. InFIGURE 2, the drum 20 referred to above is shown, this drum beingutilized for securing a master thereon in a suitable manner. Cooperatingwith the drum 2|) is an impression roll 32. Adjacent the drum andimpression roll in anterior direction with respect to the direction ofpassage of copy sheets through the machine, is a pair of cooperatingrolls which include a moistening roll 34 and pressure roll 36. A stackof copy sheets 38 is placed on a feed table 40 and are fed into themachine for passage between the rolls 34 and 36, and thereafter betweenthe drum 20 and roll 32. The roll 34 is for the purpose of moisteningeach copy sheet as it passes thereby, and the two rolls 34 and 36together grip the copy sheet therebetween and feed it to the drum 20 androll 22. Thereafter, rotation of the drum 20 and roll 32 feeds the copysheet therebetween and subsequent to making an impression thereon fromthe master on the drum, the copy sheet is discharged into a suitablereceiving tray (not shown).

The copy sheets 38 on the feed table upon being fed successivelytherefrom into the machine, are guided into proper relation to the rolls34 and 36 by means of deflectors 42 and 44 extending transversely acrossthe machine and forming a concave receiving and deflecting zoneoperative for guiding the leading edges of the copy sheets betweenterminal portions 46 of the deflectors which are positioned for guidingthe sheets to the bight of the rolls 34 and 36.

The feed means 26 referred to above, includes a pair of feed Wheels 48mounted on a rotatable shaft 50 which extends through arcuate slots 52(FIGURE 2) in the side plates 18 for up and down movements therein.Associatedwith the feed wheels 48 and shaft 50 is a bar 54 positionedabove the shaft and secured in a rigidly assembly therewith, serving asa means for grasping by the handfor lifting the feed wheels. Uponrotation of the feecl'wheels 48 in appropriate direction(counterclockwise as viewed in'FIGURES 2 and 3), the top copy sheet 38is frictionally gripped thereby and fed from the top of the stack intothe machine as indicated by the single copy sheet designated 38a.

Rotation of the feed wheels 48, as well as movement of other movingparts of the duplicating machine including the roll 34 and drum 20 whichare positively driven, is effected by the motor 24 and'suitable drivetransmission means, 'a portion of which is shown in FIGURE 3 and all ofwhich are disclosed in detail in the above-mentioned copendingapplication. The portions of the drive transmission means shown hereininclude a belt 56 connected between a pulley 58 on the drive shaft ofthe motor and a pulley 60 mounted on the adjacent side plate 18. Anotherbelt 62 is' trained on a pulley on the shaft bearing pulley 6G and apulley 64 on the shaft on which the drum 20 is mounted. Also provided isdrive transmission means between the'drum 20 and the shaft 50 on whichthe feed wheels are mounted. This latter drive transmission means is onthe side of the machine opposite that shown in FIGURE 3 or on the lefthand side as viewed in FIGURE 1; it terminates in a gear 65 (FIG. 6)having connection with the shaft 50, as brought out in detailhereinbelow.

- The assembly including the shaft 50 and bar 54, in the operation ofthe machine, is adapted to be lowered by. gravity, the feed Wheels 48resting on the top copy sheet of the stack. This position is shown inFIGURE 2. As the stack is depleted the assembly lowers with the feedwheels constantly bearing on the stack and engaging the top sheetthereof. Upon removal of the last copy sheet'from the feed table thefeed wheels drop into a trough or groove 66 formed in the feed table 49.In

loading copy sheets in the machine in normal'use thereof,

the operator grasps the bar 54 and lifts the assembly in.- eluding thatbar and the shaft 50 to an uppermost position in which the bar engagesthe upper edge of the slots '52. The assembly is latched in suchposition as disclosed fully in the above mentioned patent, and while inthat position "a stack of copy sheets is placed on the feed table in theposition shown in. FIGURE 2; thereafter the assembly is released and letdown on the stack to the position shown in FIGURE 2 in which the feedwheels engage and rest on the stack. Further details of the operation ofthese feed wheels will be referred to again here in'below' in'connctio'n with the pressure control means.

The assembly including the shaft 50 with the feed wheels thereon and thebar 54 is mounted for its up and down movements on pivoted arms onopposite sides of the machine, one of these arms'being shown at 68 inFIG- URES 3 and 6 and the other at 69 in FIGURE 6. The arms arepositioned on the outer sides of the respective side plates 18. It willbe understood that these arms are mounted on a common horizontaltransverse axis contained in the pin or stud 70 on which the arm 68 ispivotally mounted. The shaft 50 is mounted at one end in the swingingend of the arm 68 indicated at 72, in an arrangement which may include abushing or bearing 74 secured in the end of the arm and in which acylindrical portion 76 of the shaft is rotatably mounted. The oppositeend of the shaft may be mounted by means illustrated in FIGURE 6 whichincludes a hub portion. 78 of the gear 65. The details of this mountingmeans will be given hereinbelow, it being sufiicient to state at thepresent point that upon rotation of the gear 65 the shaft 50 is rotated.v

The swinging end portion 72 of the arm 68 has an upstanding extension 80in which the adjacent end of the bar 54 is mounted. This mounting mayassume any practical form such as that shown in FIGURE 5 where the barhas a reduced terminal portion projected through an aperture in theextension 80 and secured by a nut 82. The arm 68 also had a downwardlyextending part 84, including certain operating parts brought out indetail in the above mentioned copending application but which do notenter into the present invention and are not described in detail'herein,this part being omitted at least partially from FIGURE 5.

Means is provided for biasing the arm 68, and thus the feed wheels 48,upwardly so as to partially counterbalance the action of gravitythereon. This means may be in a form of wire spring 86 having a centralcoiled portion on the stud 70, one end portion 88 engaging a fixedelement 99 on the frame of the machine, and another end portion 92engaging under the arm 68 adiacent the swinging end of the latter. Thepressure control means indicated at 30 is arranged to operate on the arm68, and acting through this arm and the shaft 58 it controls thepressure exerted by the feed wheels 48 on the stack of copy sheets. Thispressure control means is mounted bodily on a suitable member of theframe structure of the machine such as bracket 94 which is utilized forsupporting one end of the fuel supply tank 22. This bracket 94 has oneend portion 96' secured to the respective side plate 18 as best shown inFIGURE 5 and another portion 98 spaced outwardly therefrom. The pressurecontrol means includes a mounting member indicated in its entirety at100 secured rigidly to the portion 98 of the bracket 94 by suitablemeans such as screws 102. This member has a downwardly extending legterminating at a level adjacent to that of the pivot axis of the arm 68.An adjusting lever 106 is pivoted at one end at 108 on the lower end ofthe leg 104 on a horizontal transverse axis and its opposite swingingend 110 is disposed adjacent the stud 70. A tension spring 112 isinterconnected between the swinging end of the adjusting lever 106 and apin 114 fixedly secured to the arm 68 adjacent the swinging end of thelatter.

A control link 116 is mounted on the mounting memher 100 for slidingmovements in a generally vertical direction or such direction that uponsliding thereof the adjusting member 106 is swung in generally up anddown movements. The connection. for enabling such sliding movementincludes a stud 118 fixedly mounted on the member 100 adjacent the topthereof and fitted in a longitudinal slot 120 in the link 116. A smallerstud or rivet 122 is also secured to the member 100 and extended throughthe slot 120. The elements 118 and 122 provide suitable guidingmovements for maintaining the link 116 in properly aligned longitudinaldirection. The stud 118 provides a connecting means for one end of atension spring 124 for biasing the link 116 upwardly, the opposite endof the spring being connected to a tab 126 on the link.

Manual adjustment of the link 116 is provided by means of a cam 128having a plurality of depressions 130 adapted to selectively receive aroller or cam follower 132 on the upper end of the link. The cam oreccentric 128 is mounted on the outer end of the shaft 134 mounted inthe adjacent side plate 18, a spacer 136 being interposed between thecam and the side plate. A manual control knob 138 is mounted on theinner end of the shaft, on the inner side of the side plate, positionedfor convenient grasping by the hand for manual manipulations. The cam oreccentric 128 upon rotation thereof to different positions is operativefor positioning the link 116 in corresponding positions, according towhich of the depressions 130, and corresponding distances from the axisof rotation, the cam follower is positioned. The control knob 138 may beprovided with appropriate inscriptions as in FIGURE 1 for indicating thepressure imposed on the feed wheels according to the respective settingof the pressure control means.

The pressure control means '30 is operative for imposing variouspressures on the feed wheels 48, which may be positive or negativepressures, i.e. positive pressure or downward pressure added to theeffect of gravity on the feed wheels, and negative pressure or upwardpressure counter to the effect of gravity. Referring more par ticularlyto FIGURE 4, where the arm 68 is in an upper position, a reference line140 is shown drawn through the pivot axis of the arm 68 and the pin 114.The adjusting lever 106 is also in an upper position corresponding to anupper position of the sliding link 116 as controlled by the position ofthe cam 128. In this position of the lever 106 the swinging end thereofis above the reference line 140 and therefore produces an upwardlybiasing effect or negative pressure on the arm 68. The adjusting lever-6 is swingable to a lower position indicating in dotdash lines inFIGURE 4 where the swinging end of the lever is below the reference line140. In this position the tension spring 112 produces a downwardlybiasing effect or positive pressure on the arm 68. It will be understoodthat the lever 106 may assume any of a plurality of positions betweenits uppermost and lowermost positions. The swinging end of the adjustingmember 106 is horizontally adjacent the transverse pivotal axis of thearm 68, an ideal position being in effective vertical alignment withthat axis, but in the interest of compactness it is displaced slightlytherefrom. The pivot axis of the control lever 106 at the lower end ofthe leg 104 is horizontally adjacent the path of movement of the shaft50, to the end of providing substantial length -to the lever 106 andconsequent substantial throw thereof, for exerting correspondingpressure on the feed wheels. Adjustments of the pressure control meansmay be made easily and simply, even while the machine is in operation byadjusting the knob 138.

The feed wheels 48 are preferably two in number and for best effect theyshould engage the copy sheets adjacent the side edges thereof. A feedtable of a kind well adapted for use in connection with the presentinvention and as disclosed in detail in my copending application SerialNumber 795,699, filed February 26, 1959, includes adjustable side guides144 (FIG. 1) for engaging the side edges of the copy sheets placed onthe feed table. These side guides are adjustable transversely of thefeed table and in order to provide for the desired position of the feedwheels as indicated above, the latter are made adjustable along theshaft 50 by means of a novel construction embodied in the presentinvention. The positioning of the feed wheels 48 in relation to thewidth of the particular size of copy sheets being used has certainrelation with the degree of pressure imposed on the feed wheels underthe control of the pressure control means 30. The copy sheets arenormally engaged at side edges by sheet release control means forrestraining all but the top copy sheet from being fed from the feedtable, in a single feeding operation. As mentioned above, the pressureapplied to the copy sheets according to the present invention isselected according to the weight or thickness ofthe copy sheets since agreater pressure intended for a heavy copy sheet may cause feeding ofmore than one light copy sheet at a time, while a lesser pressureintended for light copy sheets may be ineffective for feeding a heaviersheet. In addition to providing the desired selected pressure, for bestresults in feeding, the feed wheels 48 should engage the copy sheetsadjacent the side edges thereof or at locations transversely adjacentthe means for controlling the release of the copy sheets. Accordingly,the sheet wheels 48 are made adjustable along the shaft 50, as stated,by novel means shown in detail in FIGURES 6 to 13, inclusive, disclosedand claimed in copending divisional application Serial No. 186,476,filed April 10, 1962.

The shaft 50 includes the cylindrical portion 76 referred to above andthe main central portion indicated at 144 is polygonal, and preferablysquare, in cross section. The cylindrical portion 76 maybe larger thanthe greatest cross sectional dimension of the square portion 144; at theopposite end is another cylindrical portion 146 which is no greater thanthe side-to-side cross sectional dimension of the portion 144, andpreferably is substantially equal thereto. This cylindrical portion 146forms a means for mounting that end of the shaft in the hub member 78,as well as to facilitate insertion of that end of the shaft into thecentral holes of the feed wheels, the feed wheels being removable fromthe shaft as described hereinbelow. The cylindrical portion 146 isfitted in axial bore 148.in the hub member 78 and is held thereinagainst axial displacement by means of a removable securing means 150which includes a pin 152 secured at the central portion of a clip 154.The clip 154 is of spring material and has side arms of arcuate shapereleasably engaging. around the hub member 78 with the pin 152 projectedthrough a transverse hole 156 in the end of the shaft and aligned holes158 in the hub member 78. Removal of the securing means 150 may beeffected by flexing the side arm portions of the clip 154 outwardly andremoving it from the hub member, withdrawing the pin 152 from the holes156 and 15 8. The shaft is permitted axial movement in the arm 68 toremove the cylindrical portion 176 from the hub member 7' The feedwheels 48 are preferably of rubber or rubber like material for providinga high degree of friction with the copy sheets for assuring removal ofthe copy sheets from the stack. If desired the peripheral surface of thefeed wheels 48 may be ribbed or serrated for increasing their frictionwith the copy sheets. The feed wheels may be of any desired size andproportions and each has a central axial hole 160 therethrough (FIGURE11) of polygonal shape corresponding to that of the portion 144 of theshaft, or square. The hole is also similar in transverse dimensions tothe square portion of the shaft, but the material of the feed wheels ishighly resilient and at any given time this hole may be stretched to asize greater than that of the shaft, and it is so stretched by theinserts 162 which are placed in the wheels and interposed betweenthe'side surfaces of the holes and the shaft. These inserts 162 arepreferably steel strips having a central elongated portion 164 and anend portion 166 at each end turned transversely to the main portion;these end portions may be slightly tapered as indicated in FIGURES 7, 10and 11. These inserts are placed in the hole in the wheel with thecentral elongated portion 164 extending axially and fitted flat to thecorresponding side surfaces of the hole with the end portions 166engaging the side surfaces of the wheel and directed radially outwardly.Preferably, the side surfaces of the wheel are provided with recesses orcavities 168 as shown in FIGURES 8 and 11 of suitable dimensions forsnugly receiving these end portions 166 and establishing an outer flushsurface containing the surfaces'of the wheel and the outer surfaces ofthe end portions.

These inserts may be-of a Width-similar to or slightly greater than thetransverse edge dimension of the hole in contracted condition of thewheel and when inserted in the hole with the wheeloif of the shaft inthe position indicated in FIGURE 10, the edges of each insert may belapped with the edge of adjacent insert, in one direction. The wheel isplaced on the shaft-by inserting the small cylindrical portion 146 intothe hole defined by the inserts. The cylindrical shape 146 facilitatesinsertion of the end ofthe shaft into-the hole, enabling cocking orcanting positions of the shaft and wedging the inserts outwardly as thecylindricalportionis forced .into the hole. The diameter of'the shaftportion 146 being sub- 'stantially equivalent to side-t'o-side dimensionof the square portion of the shaft, forces the inserts radiallyoutwardly and'positions them so as to facilitate insertion of the squareportion into the hole. Upon outward expansion 'of the inserts "thematerial of the wheel is ex.-

panded, or stretched outwardly to a position indicated in.

FIGURE 7. The relativev relationsiand dimensions of FIGURES 7, l and'llare slightly exaggerated for convenience in depicting the effectproduced, the object being to show that the square portionof the shaftexpands the material of the wheel substantially so that high frictionengagement is established between the inserts and the shaft. The insertsand shaft beingof rigid material enable the fe'ed wheels to'beslid alongthe shaft upon ap' plication of appropriate pressure as by the hand, ascontrasted with the'objectionable dragging effect produced betweenrubber and steel. However, the contracting eifect'of the resilientmaterial of the wheel is sufiicient to establish such high degreeof'friction between the inserts and'shaft as to provide the necessarygripping effect to retain the feed wheels in set or adjusted positionagainst ordinary forces involved in the use of the machine.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it willbeapparent that various changes may be made in theform, construction andarrangement of theparts without departing from the spirit and scope oftheinventionor sacrificing any of its material'advantages, the form'hereinbefore jdescribedbeing merely a preferred embodiment thereof.

Iclaim: V V I 1. In a duplicating machine having means for passing copysheets therethrough and imprinting thereon in their passagetherethrough, and means for supporting a stack of copy sheets at anentrance end of the machine, the combination comprising, feed wheels,means supporting the feed wheels including at least one arm connected ata vertically swinging end withthe feed wheels, and pivoted at its otherend on a transverse axis, the feed wheels being adapted to descend bygravity, an adjusting lever pivoted at one end adjacent the path ofvertical movement of the-feed wheels at a height substantiallyequivalent to that of said transverse'axis of the arm and itself beingpivoted on a tranverse axis and having a vertically swinging endhorizontally adjacent the pivot axis of said arm, a tension springconnected between the swinging ends of said arm and lever, a linkslidably mounted and connected with said lever between the ends of thelatter and operative in response to sliding movement for swinging the 7copy sheets therethrough and imprinting thereon in their passagetherethrough, and means for supporting a stack of copy sheets at anentrance end of the machine for feeding of them therefrom into themachine, the combination comprising, feed means mounted in the-machineand frictionally engageable with the top one of a stack of copy sheetson said supporting means for feeding it therefrom into the machine, armsmounting said feed means at one end' of the arms for generally verticalswinging movements about a transverse pivot axis at the other end of thearms and spaced generally horizontally from the feed means, said feedmeans being constantly subject to lowering by gravity, adjusting armspivoted on a transverse axis adjacent the line of movement of the freeends of the mounting arms, and extending generally horizontally withtheir-free ends swingable generally-vertically inlinesadjacent the firstpivot axis, tension spring means interconnecting the free ends oftheadjusting arms and the free ends'of the mounting arms and operative forproducing a constant bias on the mounting arms, and manually actuatablemeans for adjustably setting the adjusting arms in any of a plurality ofpositions in arange at one end of which the free'ends of-the adjustingarms are above the axis of the mounting arms and at the other end ofwhich they are below the last named axis.

3. The invention set out in claim 2 in which non-yielding stop means isprovided for limiting the upward movement of the adjusting arms, andspring means is provided for biasing'the adjusting arms upwardly.

4. The invention setout'in claim 3 in which said stop meansincludesamanually settable cam having a plurality of positions forselectively predetermining the positions of said adjusting armsthroughout their said range.

5. The invention set out in claim 1 in which the feed means includesa-pair of feed wheels on a rotatable shaft, and the feed means isconstantly subject to gravity and free to' lower thereby as determinedby thedepth of the stack of sheets and throughout the range of thestack.

6. The combination set out in claim Sin which the feed wheels areadjustable along said shaft throughout substantially the full width ofthe sheet supporting means whereby to provide for engaging copy sheetsof diflerent widths by the feed wheels at similar and, correspondingpositions.

7. The invention set out in claim 6 in which means is included fordetachably mounting 'said shaft, and said feed wheels are removable fromthe shaft over the ends thereof.

